I have the same issue on 50mb as well as my current 100mb. I live in the Neath area and I get my full speed 99% of the time day or night on pretty much most websites.
But when it comes to YouTube it's 50/50 whether I get good speeds or not. Some videos at 1080 will load instantly at 5-6MB/s and some 240 or 360 videos barley load at 90-100KB/s at then buffer and play, buffer and play. It's a bloody pain

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